Internet Gateways (IGW) Flashcards
What is an AWS Public Zone?
AWS zone that hosts only aws services, such as S3, dynamodb, sqs, etc
What are the names of the two public facing zones?
1) AWS Public Zone
2) Public Internet
True or false: traffic leaving your vpc to access aws public services will need to traverse the internet before arriving to the aws public services.
False; traffic sourced from your vpc to the aws public zone never leaves the aws network.
From a vpc, what is used to access the aws public zone or the internet?
An internet gateway (IGW)
What is an internet gateway?
A VPC component that allows communication between the vpc and the aws public zone and/or the internet.
True or false: internet gateways support only ipv4 addresses.
False; they also support ipv6 addresses.
How many VPCs can be attached to an IGW?
Only one vpc can be attached to one gateway, so one VPC per an IGW.
True or false: IGWs can only attach to one Availability zone within one region.
False; One IGW can attach to multiple availability zones that are only in the same region.
What are the 4 steps to enable private subnets access to the internet?
Create an internet gateway and attach it to your VPC.
Add a route to the route table for the subnet that directs internet-bound traffic to the internet gateway.
Ensure that instances in your subnet have a public IPv4 address or an IPv6 address.
Ensure that your security groups and network access control lists allow the desired internet traffic to flow to and from your instances.
When using IPv6, what kind of IGW should be used? and why?
The Egress IGW should be used to only allow outbound traffic from the vpc to the internet. This blocks inbound traffic.
How many internet gateway objects can be attached to one vpc?
Two: the internet gateway and the egress internet gateway.
What are the steps to attaching an internet gateway and associating public subnets to it? Hint: 5 steps
1) Create the IGW
2) Enable the subnet to auto-assign public subnets
3) Create a custom route table
4) Create a default route for both ipv4 and ipv6 and attach the routes to the gateway
5) Associate the subnets to this route table
